Conventionally, there has been known a bag transfer device (gripper device) including a plurality of gripper pairs (pairs of right and left grippers) provided on a table that is horizontally rotated, and a distance adjustment mechanism for adjusting a distance between the right and left grippers in each of the pairs.
For example, Japanese patent application publication No. 2011-031896 discloses a rotary packaging machine that is capable of adjusting a holding angle of a holding arm for holding a packaging member. In addition, Japanese patent application publication No. 2004-244085 discloses a so-called W-type bagging and packaging device in which both of a bag making device and a rotary bagging and packaging device are provided to perform packing operation of two bags held by grippers while the two bags are juxtaposed side by side.